Patient survival and cardiovascular events after kidney-pancreas transplantation: comparison with kidney transplantation alone in uremic IDDM patients

Copper metabolism and its role in diabetic complications: A review

Disturbances in copper (Cu) homeostasis have been observed in diabetes and associated complications. Cu is an essential micronutrient that plays important roles in various fundamental biological processes. For example, diabetic cardiomyopathy is associated with elevated levels of Cu in the serum and tissues. Therefore, targeting Cu may be a novel treatment strategy for diabetic complications. This review provides an overview of physiological Cu metabolism and homeostasis, followed by a discussion of Cu metabolism disorders observed during the occurrence and progression of diabetic complications. Finally, we discuss the recent therapeutic advances in the use of Cu coordination complexes as treatments for diabetic complications and their potential mechanisms of action. This review contributes to a complete understanding of the role of Cu in diabetic complications and demonstrates the broad application prospects of Cu-coordinated compounds as potential therapeutic agents.

HMGN1 down-regulation in the diabetic kidney attenuates tubular cells injury and protects against renal inflammation via suppressing MCP-1 and KIM-1 expression through TLR4

BACKGROUND

Renal tubular injury, accompanied by damaging inflammation, has been identified to drive diabetic kidney disease (DKD) toward end-stage renal disease. However, it is unclear how damage-associated molecular patterns (DAMPs) activate innate immunity to mediate tubular epithelial cell (TEC) injury, which in turn causes with subsequent sterile inflammation in diabetic kidneys. High mobility group nucleosome-binding protein 1 (HMGN1) is a novel DAMP that contributes to generating the innate immune response. In this study, we focused on determining whether HMGN1 is involved in DKD progression.

METHODS

Streptozotocin (STZ)-induced diabetic mice model was established. Then we downrergulated HMGN1 expression in kidney with or without HMGN1 administration. The renal dysfunction and morphological lesions in the kidneys were evaluated. The expressions of KIM-1, MCP-1, F4/80, CD68, and HMGN1/TLR4 signaling were examined in the renal tissue. In vitro, HK2 cells were exposed in the high glucose with or without HMGN1, and further pre-incubated with TAK242 was applied to elucidate the underlying mechanism.

RESULTS

We demonstrated that HMGN1 was upregulated in the tubular epithelial cells of streptozotocin (STZ)-induced type 1 and type 2 diabetic mouse kidneys compared to controls, while being positively correlated with increased TLR4, KIM-1, and MCP-1. Down-regulation of renal HMGN1 attenuated diabetic kidney injury, decreased the TLR4, KIM-1, and MCP-1 expression levels, and reduced interstitial infiltrating macrophages. However, these phenotypes were reversed after administration of HMGN1. In HK-2 cells, HMGN1 promoted the expression of KIM-1 and MCP-1 via regulating MyD88/NF-κB pathway; inhibition of TLR4 effectively diminished the in vitro response to HMGN1.

CONCLUSIONS

Our study provides novel insight into HMGN1 signaling mechanisms that contribute to tubular sterile injury and low-grade inflammation in DKD. The study findings may help to develop new HMGN1-targeted approaches as therapy for immune-mediated kidney damage rather than as an anti-infection treatments.

The anti-inflammatory and immunological properties of SGLT-2 inhibitors

BACKGROUND

Sodium-glucose cotransporter-2 inhibitors (SGLT-2i) are antidiabetic oral drugs that act on proximal renal tubules promoting renal glucose excretion. Although SGLT-2i belong to the class of hypoglycemic agents, in the last years great interest has emerged in studying their pleiotropic effects, beyond their ability to lower glucose levels.

PURPOSE

In this review we are describing the anti-inflammatory and immunological properties of SGLT-2i; furthermore, we are addressing how the mechanisms associated with the aforementioned anti-inflammatory properties may contribute to the beneficial effects of SGLT-2i in diabetes.

METHODS

A systematic search was undertaken for studies related the properties of SGLT-2i in reducing the inflammatory milieu of acute and chronic disease by acting on the immune system, independently by glycemia.

RESULTS

Recently, some data described the anti-inflammatory and immunological properties of SGLT-2 in both pre-clinical and clinical studies. Numerous data confirmed the cardio- and -renal protective effects of SGLT-2i in patients with heart failure and kidney diseases, with or without diabetes.

CONCLUSIONS

SGLT-2i are promising drugs with anti-inflammatory and immunological properties. Despite the mechanism of action of SGLT-2i is not fully understood, these drugs demonstrated anti-inflammatory effects, which may help in keeping under control the variety of complications associated with diabetes.

METTL14 promotes the development of diabetic kidney disease by regulating m6A modification of TUG1

BACKGROUND

Diabetic kidney disease (DKD) is one of the most common diabetic complications. Endoplasmic reticulum stress (ERS) is an important step for renal tubular epithelial cell apoptosis during DKD progression. Herein, the role and regulatory mechanism of METTL14 in ERS during DKD progression were investigated.

METHODS

DKD animal and cell models were established by streptozotocin (STZ) and high glucose (HG), respectively. HE and Masson staining were performed to analyze renal lesions in DKD mouse. Cell viability and proliferation were determined by MTT and EdU staining, respectively. HK2 cell apoptosis was analyzed by flow cytometry. TUG1 m6A level was determined by Me-RIP. The interaction between TUG1, LIN28B and MAPK1 was analyzed by RIP and RNA pull-down assays.

RESULTS

HG stimulation promoted apoptosis and increased ERS marker proteins (GRP78, CHOP and caspase12) expression in HK2 cells, while these changes were reversed by METTL14 knockdown. METTL14 inhibited TUG1 stability and expression level in an m6A-dependent manner. As expected, TUG1 knockdown abrogated METTL14 knockdown's inhibition on HG-induced HK2 cell apoptosis and ERS. In addition, TUG1 inactivated MAPK1/ERK signaling by binding with LIN28B. And TUG1 overexpression's repression on HG-induced HK2 cell apoptosis and ERS was abrogated by MAPK1 signaling activation. Meanwhile, METTL14 knockdown or TUG1 overexpression protected against STZ-induced renal lesions and renal fibrosis in DKD mouse.

CONCLUSION

METTL14 promoted renal tubular epithelial cell apoptosis and ERS by activating MAPK/ERK pathway through m6A modification of TUG1, thereby accelerating DKD progression.

Broadening horizons in mechanisms, management, and treatment of diabetic kidney disease

Diabetic kidney disease (DKD) is the first cause of end-stage kidney disease in patients with diabetes and its prevalence is increasing worldwide. It encompasses histological alterations that mainly affect the glomerular filtration unit, which include thickening of the basement membrane, mesangial cell proliferation, endothelial alteration, and podocyte injury. These morphological abnormalities further result in a persistent increase of urinary albumin-to-creatinine ratio and in a reduction of the estimated glomerular filtration rate. Several molecular and cellular mechanisms have been recognized, up to date, as major players in mediating such clinical and histological features and many more are being under investigation. This review summarizes the most recent advances in understanding cell death mechanisms, intracellular signaling pathways and molecular effectors that play a role in the onset and progression of diabetic kidney damage. Some of those molecular and cellular mechanisms have been already successfully targeted in preclinical models of DKD and, in some cases, strategies have been tested in clinical trials. Finally, this report sheds light on the relevance of novel pathways that may become therapeutic targets for future applications in DKD.

Recent Advancements in the Medical Treatment of Diabetic Retinal Disease

Diabetic retinal disease remains one of the most common complications of diabetes mellitus (DM) and a leading cause of preventable blindness. The mainstay of management involves glycemic control, intravitreal, and laser therapy. However, intravitreal therapy commonly requires frequent hospital visits and some patients fail to achieve a significant improvement in vision. Novel and long-acting therapies targeting a range of pathways are warranted, while evidence to support optimal combinations of treatments is currently insufficient. Improved understanding of the molecular pathways involved in pathogenesis is driving the development of therapeutic agents not only targeting visible microvascular disease and metabolic derangements, but also inflammation and accelerated retinal neurodegeneration. This review summarizes the current and emerging treatments of diabetic retinal diseases and provides an insight into the future of managing this important condition.

Acute and long-term disruption of glycometabolic control after SARS-CoV-2 infection

Patients with coronavirus disease 2019 (COVID-19) are reported to have a greater prevalence of hyperglycaemia. Cytokine release as a consequence of severe acute respiratory syndrome coronavirus 2 infection may precipitate the onset of metabolic alterations by affecting glucose homeostasis. Here we describe abnormalities in glycometabolic control, insulin resistance and beta cell function in patients with COVID-19 without any pre-existing history or diagnosis of diabetes, and document glycaemic abnormalities in recovered patients 2 months after onset of disease. In a cohort of 551 patients hospitalized for COVID-19 in Italy, we found that 46% of patients were hyperglycaemic, whereas 27% were normoglycaemic. Using clinical assays and continuous glucose monitoring in a subset of patients, we detected altered glycometabolic control, with insulin resistance and an abnormal cytokine profile, even in normoglycaemic patients. Glycaemic abnormalities can be detected for at least 2 months in patients who recovered from COVID-19. Our data demonstrate that COVID-19 is associated with aberrant glycometabolic control, which can persist even after recovery, suggesting that further investigation of metabolic abnormalities in the context of long COVID is warranted.

Outcomes of pancreas transplantation in older diabetic patients

OBJECTIVE

Improvement in insulin alternatives is leading to a delayed presentation of microvascular and macrovascular complications of diabetes. The objective of this study was to evaluate the long-term outcomes of older (≥50 years) diabetic patients who receive a pancreas transplantation (PT).

RESEARCH DESIGN AND METHODS

We retrospectively evaluated all 338 PTs performed at our center between 2000 and 2016 (mean follow-up 9.4±4.9 years). Recipient and graft survivals were estimated for up to 10 years after PT. Major adverse cardiovascular events (MACEs) before and after PT were included in the analysis.

RESULTS

Thirty-nine patients (12%) were ≥50 years old (52.7±2.3 years) at the day of PT, of which 29 received a simultaneous pancreas-kidney transplantation (SPK) and 10 a pancreas after kidney transplantation (PAK). SPK recipients were first transplants, whereas in the PAK up to 50% were pancreas re-transplantations. Recipient and pancreas graft survivals at 10 years were similar between the group <50 years old and the older group for both SPK and PAK (log-rank p>0.05). The prevalence of MACE prior to PT was similar between both groups (31% vs 29%). Following PT, older recipients presented inferior post-transplant MACE-free survival. In a multivariate regression model, diabetes vintage (HR 1.054, p=0.03) and pre-transplantation MACE (HR 1.98, p=0.011), but not recipient age (HR 1.45, p=0.339), were associated with post-transplant MACE.

CONCLUSIONS

Long-term survival of older pancreas transplant recipients are similar to younger counterparts. Diabetes vintage, but not age, increased the risk of post-transplantation MACE. These results suggest pancreas transplantation is a valuable treatment alternative to older diabetic patients.

Citrate anion improves chronic dialysis efficacy, reduces systemic inflammation and prevents Chemerin-mediated microvascular injury

Systemic inflammation and uremic toxins (UT) determine the increased cardiovascular mortality observed in chronic hemodialysis (HD) patients. Among UT, the adipokine Chemerin induces vascular dysfunction by targeting both endothelial and vascular smooth muscular cells (EC and VSMC). As Citrate anion modulates oxidative metabolism, systemic inflammation and vascular function, we evaluated whether citrate-buffered dialysis improves HD efficiency, inflammatory parameters and chemerin-mediated microvascular injury. 45 patients were treated in sequence with acetate, citrate and, again, acetate-buffered dialysis solution (3 months per interval). At study admission and after each treatment switch, we evaluated dialysis efficacy and circulating levels of chemerin and different inflammatory biomarkers. In vitro, we stimulated EC and VSMC with patients’ plasma and we investigated the role of chemerin as UT. Citrate dialysis increased HD efficacy and reduced plasma levels of CRP, fibrinogen, IL6 and chemerin. In vitro, patients’ plasma induced EC and VSMC dysfunction. These effects were reduced by citrate-buffered solutions and paralleled by the decrease of chemerin levels. Consistently, chemerin receptor knockdown reduced EC and VSMC dysfunction. In conclusion, Switching from acetate to citrate improved dialysis efficacy and inflammatory parameters; in vitro, chemerin-induced EC and VSMC injury were decreased by using citrate as dialysis buffer.

Pancreas transplantation in older patients is safe, but patient selection is paramount

Pancreas transplant outcomes have progressively improved. Despite this, some centers have continued to employ historical age limits for pancreas transplant candidates. We sought to determine the importance of chronological age in determining patient and graft survival rates after pancreas transplantation. A single-center, retrospective study of adult, deceased donor simultaneous pancreas and kidney (SPK) and solitary pancreas transplants (SP, including pancreas transplant alone and pancreas after kidney transplants) in recipients ≥ 55 years (55 + ), occurring between July 1, 1999, and June 30, 2012, was performed. Seven-hundred and forty patients underwent pancreas transplantation, of which 28 patients were 55 + . Patient survival was comparable for younger and older pancreas transplant recipients. Both non-death-censored and death-censored pancreatic graft survival rates were similar in younger and in older patients. Patients aged 45-54 and those aged 55 +  had more frequent cardiovascular events than younger pancreas transplant recipients. There was no difference in renal graft survival for SPK patients when compared with diabetic kidney transplant alone recipients aged 55 years and older. Older pancreas transplant recipients had acceptable long-term patient and graft survival rates, although complications may occur. Chronological age alone should not exclude a patient for pancreas transplant candidacy.

PI3Kγ Deficient NOD-Mice Are Protected from Diabetes by Restoring the Balance of Regulatory to Effector-T-Cells

With a steady increase in its incidence and lack of curative treatment, type 1 diabetes (T1D) has emerged as a major health problem worldwide. To design novel effective therapies, there is a pressing need to identify regulatory targets controlling the balance of autoreactive to regulatory-T-cells (Tregs). We previously showed that the inhibition of the γ-subunit of the Phosphoinositide-3-kinase (PI3K), significantly suppress autoimmune-diabetes. To further delineate the mechanisms and the selectivity of specific immune modulation by PI3Kγ-inhibition, we developed a new NOD mouse model of T1D lacking the γ-subunit of PI3K. Strikingly, the loss of PI3Kγ protected 92% of the NOD-mice from developing spontaneous diabetes. The NOD.PI3Kγ-/- mice are protected from insulitis secondary to a defect in CD4 and CD8 autoreactive-T-cells activation and survival. In addition, PI3Kγ-deficiency promoted Treg generation in-vitro and in-vivo. Furthermore, PI3Kγ-inhibitor (AS605240) inhibited proliferation and cytokine production of a human CD4+ T-cell clone specific for GAD555-567 peptide that was isolated from a patient with T1D. These studies demonstrate the key role of the PI3Kγ pathway in regulating autoimmune-diabetes and provide rationales for future devise of anti- PI3Kγ therapy in T1D.

Pancreatic Transplantation: Evaluation and Management

More than 2 million people in the United States have type 1 diabetes mellitus. Pancreatic transplantation has emerged as the single most effective means of achieving normal glucose homeostasis in this patient population. Newer immunosuppressive agents and surgical techniques continue to evolve, resulting in improved long-term graft and patient survival. Herein, an understanding of the evaluation, technical aspects, and perioperative management of pancreas transplantation is outlined.

Effects of restoring normoglycemia in type 1 diabetes on inflammatory profile and renal extracellular matrix structure after simultaneous pancreas and kidney transplantation

AIMS

Patients with type 1 diabetes and end-stage renal disease with simultaneous pancreas and kidney (SPK) or kidney transplants alone (KA) were recruited 9-12 years post transplantation. We investigated differences between these groups with regard to inflammatory parameters and long-term structural changes in kidneys.

METHODS

Blood samples were analyzed by ELISA and multiplex for chemokines, cytokines, growth factors, cell adhesion molecules and matrix metalloproteinases. Kidney graft biopsies were analyzed by electron microscopy for glomerular basement membrane thickness. Heparan- and chondroitin sulfate disaccharide structures were determined by size exclusion chromatography mass-spectrometry.

RESULTS

The SPK and the KA group had average glycated hemoglobin A1c (HbA1c) of 5.8% (40 mmol/mol) and 8.6% (70 mmol/mol) respectively. SPK recipients also had 16.2% lower body mass index (BMI) and 46.4% lower triglyceride levels compared with KA recipients, compatible with an improved metabolic profile in the SPK group. Plasminogen activator inhibitor (PAI-1), C-reactive protein (CRP) and vascular endothelial growth factor (VEGF) were lower in the SPK group. In kidney graft biopsies of the KA-patients an 81.2% increase in average glomerular basement membrane thickness was observed, accompanied by alterations in heparan sulfate proteoglycan structure. In addition to a decrease in 6-O-sulfated disaccharides, an increase in non-N-sulfated disaccharides with a corresponding slight decrease in N-sulfation was found in kidney biopsies from hyperglycemic patients.

CONCLUSIONS

Patients with end stage renal disease subjected to KA transplantation showed impaired inflammatory profile, increased thickness of basement membranes and distinct changes in heparan sulfate structures compared with SPK recipients.

Pretransplant coronary artery disease associated with worse clinical outcomes in pancreas transplantation

BACKGROUND

Coronary artery disease (CAD) is common in patients with type I diabetes and may be associated with worse outcomes in patients undergoing pancreas transplantation (PT). This study evaluates PT patients to determine the pre transplant prevalence of CAD and assesses the post-transplant outcomes including complications and survival.

METHODS

This study is a retrospective review of PTs from 2003 to 2011. Diagnosis of CAD required cardiac catheterization. Outcomes included: myocardial infarction (MI), stroke, and survival.

RESULTS

There were 405 transplants in 389 patients with median follow-up of 56 months. Pre transplant prevalence of CAD was 19% (n = 74). There was no increased risk of perioperative, 90-d or one-yr mortality for patients with CAD. The CAD group did have increased risk of MI (11% vs. 1%, p < 0.001) and stroke (8% vs. 3%, p = 0.02). Controlling for patient and donor age, and history of CAD, the CAD group had decreased patient survival at five yr (82% vs. 90%, p = 0.09, HR 1.77) by Cox regression.

CONCLUSIONS

Patients with type I diabetes and CAD have increased risk of MI and stroke post-pancreas transplant, with decreased five-yr survival. Patients without CAD and a negative pre transplant cardiac evaluation carry a low risk of post-transplant MI.

Follow-up of secondary diabetic complications after pancreas transplantation

PURPOSE OF REVIEW

Successful pancreas transplantation restores physiologic glycemic and metabolic control. Its effects on overall patient survival (especially for simultaneous pancreas-kidney transplantation) are clear-cut. We herein review the available literature to define the impact of pancreas transplantation on chronic complications of diabetes mellitus.

RECENT FINDINGS

With longer-term follow-up, wider patient populations, and more accurate investigational tools (clinical and functional tests, noninvasive imaging, histology, and molecular biology), growing data show that successful pancreas transplantation may slow the progression, stabilize, and even favor the regression of secondary complications of diabetes, both microvascular and macrovascular, in a relevant proportion of recipients.

SUMMARY

Patients who are referred for pancreas transplantation usually suffer from advanced chronic complications of diabetes, which have classically been deemed irreversible. A successful pancreas transplantation is often able to slow the progression, stabilize, and even reverse many microvascular and macrovascular complications of diabetes. Growing clinical evidence shows that the expected natural history of long-term diabetic complications can be significantly modified by successful pancreas transplantation.

Transplantation of the pancreas

Pancreas transplantation consistently induces insulin-independence in beta-cell-penic diabetic patients, but at the cost of major surgery and life-long immunosuppression. One year after grafting, patient survival rate now exceeds 95 % across recipient categories, while insulin independence is maintained in some 85 % of simultaneous pancreas and kidney recipients and in nearly 80 % of solitary pancreas transplant recipients. The half-life of the pancreas graft currently averages 16.7 years, being the longest among extrarenal grafts, and substantially matching the one of renal grafts from deceased donors. The difference between expected (100 %) and actual insulin-independence rate is mostly explained by technical failure in the postoperative phase, and rejection in the long-term period. Death with a functioning graft remains a further major issue, especially in uremic patients who have undergone prolonged periods of dialysis. Refinements in graft preservation, surgical techniques, immunosuppression, and prophylactic treatments are expected to further improve the results of pancreas transplantation.

Pancreas transplantation

SPK transplant is the definitive treatment of type 1 diabetes combined with end-stage renal disease. Long-term graft function can lead to improvement in diabetes-related complications and, in patients younger than 50 years, can lead to improved overall survival. PAK transplant and PA transplant do not result in similar improvements in patient survival, but with appropriate patient selection, they can improve quality of life by rendering patients insulin-free. Pancreas transplant is associated with more surgical complications and higher perioperative morbidity and mortality than KTA. Therefore, careful donor and recipient selection along with meticulous surgical technique are mandatory for optimal outcomes.

Evolution of β-Cell Replacement Therapy in Diabetes Mellitus: Pancreas Transplantation

Diabetes mellitus remains one of the leading causes of morbidity and mortality worldwide. According to the Centers for Disease Control and Prevention, approximately 23.6 million people in the United States are affected. Of these individuals, 5-10% have been diagnosed with type 1 diabetes mellitus (TIDM), an autoimmune disease. Although it often appears in childhood, T1DM may manifest at any age. The effects of T1DM can be devastating, as the disease often leads to significant secondary complications, morbidity, and decreased quality of life. Since the late 1960s, surgical treatment for diabetes mellitus has continued to evolve and has become a viable alternative to chronic insulin administration. In this review, the historical evolution, current status, graft efficacy, benefits, and complications of pancreas transplantation are explored.

Proteomics reveals novel oxidative and glycolytic mechanisms in type 1 diabetic patients' skin which are normalized by kidney-pancreas transplantation

BACKGROUND

In type 1 diabetes (T1D) vascular complications such as accelerated atherosclerosis and diffused macro-/microangiopathy are linked to chronic hyperglycemia with a mechanism that is not yet well understood. End-stage renal disease (ESRD) worsens most diabetic complications, particularly, the risk of morbidity and mortality from cardiovascular disease is increased several fold.

METHODS AND FINDINGS

We evaluated protein regulation and expression in skin biopsies obtained from T1D patients with and without ESRD, to identify pathways of persistent cellular changes linked to diabetic vascular disease. We therefore examined pathways that may be normalized by restoration of normoglycemia with kidney-pancreas (KP) transplantation. Using proteomic and ultrastructural approaches, multiple alterations in the expression of proteins involved in oxidative stress (catalase, superoxide dismutase 1, Hsp27, Hsp60, ATP synthase delta chain, and flavin reductase), aerobic and anaerobic glycolysis (ACBP, pyruvate kinase muscle isozyme, and phosphoglycerate kinase 1), and intracellular signaling (stratifin-14-3-3, S100-calcyclin, cathepsin, and PPI rotamase) as well as endothelial vascular abnormalities were identified in T1D and T1D+ESRD patients. These abnormalities were reversed after KP transplant. Increased plasma levels of malondialdehyde were observed in T1D and T1D+ESRD patients, confirming increased oxidative stress which was normalized after KP transplant.

CONCLUSIONS

Our data suggests persistent cellular changes of anti-oxidative machinery and of aerobic/anaerobic glycolysis are present in T1D and T1D+ESRD patients, and these abnormalities may play a key role in the pathogenesis of hyperglycemia-related vascular complications. Restoration of normoglycemia and removal of uremia with KP transplant can correct these abnormalities. Some of these identified pathways may become potential therapeutic targets for a new generation of drugs.

Impact of pancreas transplantation on type 1 diabetes-related complications

PURPOSE OF REVIEW

Type 1 diabetes is a chronic disease that can impact patient survival and quality of life because of acute and chronic complications. Although intensive insulin scheme treatment has been shown to reduce the incidence of diabetes-related complications, only pancreas transplantation has been shown to be able to alter them and in some cases to revert them. In this review, an extensive view of the effect of pancreas transplantation on diabetes-related complication will be described.

RECENT FINDINGS

This review will focus on patients survival, diabetic nephropathy, neuropathy, cardiovascular event, comparing their incidence in type 1 diabetic patients treated with insulin and in type 1 diabetic patients receiving kidney, kidney-pancreas or pancreas alone graft. The review will focus mostly on the papers published in the last decade, with a particular attention to those on new aspects of graft function analysis like spectroscopy. Moreover, a comparison with islet transplantation procedure will be performed.

SUMMARY

This review will give an update on the potential of pancreas transplantation, give a guide for clinical practice and help to consider pancreas transplantation as an alternative to insulin treatment for selected patients.

The evolution of diabetic chronic complications after pancreas transplantation

Pancreas transplantation is an invasive procedure that can restore and maintain normoglycemic level very successfully and for a prolonged period in DM1 patients. The procedure elevates the morbimortality rates in the first few months following the surgery if compared to kidney transplants with living donors, but it offers a better quality of life to patients.Although controversial, several studies have shown the stabilization or the improvement of some of the chronic complications related to diabetes, as well as the extra number of years of life that patients submitted to a double pancreas-kidney transplantation may gain.Recent studies have demonstrated clashing outcomes regarding isolated pancreas transplantations, a fact which reinforces the need for a more discerning selection of patients for this procedure.

Pancreas transplantation

Since the introduction of pancreas transplantation more than 40 years ago, efforts to develop more minimally invasive techniques for endocrine replacement therapy have been in progress, yet this surgical procedure still remains the treatment of choice for diabetic patients with end-stage renal failure. Many improvements have been made in the surgical techniques and immunosuppressive regimens, both of which have contributed to an increasing number of indications for pancreas transplantation. This operation can be justified on the basis that patients replace daily injections of insulin with an improved quality of life but at the expense of a major surgical procedure and lifelong immunosuppression. The various indications, categories, and outcomes of patients having a pancreas transplant are discussed, particularly with reference to the effect on long-term diabetic complications.

Transplante de pâncreas e ilhotas em portadores de diabetes melito

O transplante simultâneo de pâncreas/rim tem indicações específicas, riscos e benefícios. O procedimento, cada vez mais realizado, traz vantagens se comparado ao paciente em diálise, em relação à qualidade de vida, anos de vida ganhos e evolução das complicações crônicas. Se o paciente tiver a opção de realizar o transplante de rim com doador vivo, que apresenta sobrevida semelhante do enxerto e do paciente aos dez anos, o procedimento deverá ser considerado. O transplante de pâncreas após rim, quando efetivo, pode melhorar a evolução das complicações cardiovasculares, mas em contrapartida provoca maior mortalidade nos primeiros meses após a cirurgia. O transplante isolado de pâncreas também ocasiona a maior mortalidade pós-operatória, resultado da complexidade do procedimento e da imunossupressão. O transplante de ilhotas tem sua indicação para um seleto grupo de diabéticos com instabilidade glicêmica.

The long-term management of pancreas transplantation

Diabetes mellitus (DM) is a major health problem worldwide, which affects 18.2 million individuals (6.3% of the population) in the United States. Currently, the prevalence of Type 1 DM in the United States is estimated to be 1,000,000 individuals, and 30,000 new cases are diagnosed each year. In addition to end-stage renal disease (ESRD), DM is associated with blindness, accelerated atherosclerosis, dyslipidemia, cardio- and cerebrovascular disease, amputation, poor quality of life, and overall lifespan reduction. It accounts for more than 160,000 deaths per year in the United States alone. In 2002, the annual national direct and indirect costs of Types 1 and 2 DM exceeded $130 billion, which included hospital and physician care, laboratory tests, pharmaceutical products, and patient workdays lost because of disability or premature death. Hyperglycemia alone or in concert with hypertension is the primary factor influencing the development of major diabetic complications. From 1990 to 2001, the number of existing ESRD cases to DM increased by more than 300%, while the rate per million populations increased from 167% to 491%. The number is expected to grow 10-fold by 2030 to 1.3 million accounting for 60% of ESRD population. To date, DM is the leading indication for transplantation and is the cause of ESRD in more than 40% of all transplant recipients each year.

Influence of pancreas and kidney transplant function on recipient survival

The aim of this study was to evaluate long-term survival after simultaneous pancreas and kidney (SPK) transplantation in relation to function of both grafts. Among 67 recipients who received SPK transplants between 1988 and 2004, 35 had follow-up longer than 18 months, and were divided into: group I (n = 20), recipients with good function of both grafts; group II (n = 7), patients who had lost transplanted pancreas but had still good kidney graft function; group III (n = 8), patients who had lost both grafts. Comparison of survival rates and analysis of the reason of mortality among groups was performed. The cumulative survival rate was significantly higher in group I than in group III (after 3, 5, 10 years: 100%, 100%, 80% vs 75%, 50%, 37%, respectively). Cumulative survival rate for group II after 3, 5, 10 years was 100%, 100%, 33%, respectively. There were no significant differences in survival rates between groups I and II and between groups II and III. In group I deaths for cardiovascular event and for leukemia were noted. In group II deaths due to cardiovascular event and sepsis were observed. In group III all patients died due to cardiovascular events and the mean time from loss of pancreas and kidney graft function to death was: 75 +/- 51 months (range from 19 to 142), and 49 +/- 26 months (range 19 to 99), respectively. Good pancreas and kidney graft functions prevent death due to cardiovascular event.

Evaluation of Type 1 Diabetics for Simultaneous Pancreas-Kidney Transplantation With Regard to Cardiovascular Risk

The main cause of death for diabetic patients and patients on dialysis is coronary artery disease (CAD). The most common cause of graft loss following simultaneous pancreas and kidney transplantation (SPK) is death with a functioning graft due to CAD. Therefore, careful pretransplantation evaluation of CAD is mandatory. In our series, every patient undergoes a noninvasive cardiac function test like dobutamine stress echocardiography (DSE) or myocardial thallium scintigraphy using adenosine to induce medical stress. Thirty patients were evaluated for SPK: 15 patients with myocardial scintigraphy and 8 with DSE. Seven investigations showed pathological findings and we performed coronary angiograms, none of which showed coronary artery stenosis. Seven primary coronary angiograms were performed: four due to a history of CAD and three as a primary diagnostic. Following SPK one patient died at 21 days after transplantation due to myocardial infarction. He had a history of CAD with angioplasty and stent implantation. Noninvasive cardiac function tests like DSE or myocardial scintigraphy are reliable methods to evaluate CAD in patients with diabetic nephropathy awaiting SPK. In case of a suspicious finding or a history of CAD, a coronary angiogram should be performed to assess the need for revascularization. Following this algorithm we may further reduce the mortality of SPK.

Pancreas transplantation: indications and consequences

Pancreas transplantation continues to evolve as a strategy in the management of diabetes mellitus. The first combined pancreas-kidney transplant was reported in 1967, but pancreas transplant now represents a number of procedures, each with different indications, risks, benefits, and outcomes. This review will summarize these procedures, including their risks and outcomes in comparison to kidney transplantation alone, and how or if they affect the consequences of diabetes: hyperglycemia, hypoglycemia, and microvascular and macrovascular complications. In addition, the new risks introduced by immunosuppression will be reviewed, including infections, cancer, osteoporosis, reproductive function, and the impact of immunosuppression medications on blood pressure, lipids, and glucose tolerance. It is imperative that an endocrinologist remain involved in the care of the pancreas transplant recipient, even when glucose is normal, because of the myriad of issues encountered post transplant, including ongoing management of diabetic complications, prevention of bone loss, and screening for failure of the pancreas graft with reinstitution of treatment when indicated. Although long-term patient and graft survival have improved greatly after pancreas transplant, a multidisciplinary team is needed to maximize long-term quality, as well as quantity, of life for the pancreas transplant recipient.

Pancreas transplantation improves vascular disease in patients with type 1 diabetes

OBJECTIVE

Pancreas transplantation (PTX) normalizes glucose and improves microvascular complications, but its impact on macrovascular disease is still debated.

RESEARCH DESIGN AND METHODS

Carotid intima-media thickness (IMT), shown to correlate with cardiovascular disease (CVD) risk and events, was determined prospectively by ultrasonography in successful pancreas transplant recipients to evaluate the effect of PTX on CVD risk. Carotid IMT and CVD risk factors of pancreas transplant recipients (n = 25) were compared with three groups: individuals with type 1 diabetes without significant nephropathy (n = 20), nondiabetic kidney transplant recipients (n = 16), and normal control subjects (n = 32). Mean age of pancreas transplant recipients at the time of transplantation was 42.4 +/- 1.2 years (mean +/- SE) and duration of diabetes was 25.9 +/- 1.4 years.

RESULTS

After PTX, HbA(1c) level (P < 0.0001) decreased to normal and, whereas creatinine level (P = 0.0002) decreased, it remained elevated compared with normal control subjects (P < 0.05). Blood pressure, BMI, fasting lipid levels, smoking frequency, and use of hypolipidemic agents were unchanged. Mean carotid IMT was increased in pancreas transplant candidates but decreased by 1.8 +/- 0.1 year after PTX (P = 0.0068), no longer different from that in normal control subjects or patients with type 1 diabetes.

CONCLUSIONS

Carotid IMT improves after successful PTX within 2 years of the procedure, with normalization of HbA(1c) and improved renal function, independent of changes in lipid levels, BMI, blood pressure, smoking, or use of hypolipidemic agents. This study suggests that CVD risk, future events, and mortality should improve after PTX in the absence of other significant, untreated CVD risk factors.

Improved patient survival in recipients of simultaneous pancreas-kidney transplant compared with kidney transplant alone in patients with type 1 diabetes mellitus and end-stage renal disease

BACKGROUND

There are emerging data that simultaneous pancreas-kidney transplant (SPK) prolongs life compared with kidney transplant alone (KTA) in type 1 diabetics with end-stage renal disease. This study was a retrospective comparison of SPK with KTA in patients with type 1 diabetes.

METHODS

Between 1 January 1992 and 30 April 2002, 101 patients with type 1 diabetes were transplanted. Fifty-one of these patients received a KTA and 50 had a SPK. All patients underwent coronary angiography with surgical correction of any coronary artery disease before being listed. All patients who underwent SPK received quadruple immunosuppressive therapy consisting of antilymphocyte globulin, calcineurin inhibitor (tacrolimus or cyclosporin), azathioprine and steroids. Those who underwent KTA received calcineurin inhibitor (tacrolimus or cyclosporin), azathioprine and steroids.

RESULTS

Patient survival at 1, 3, 5 and 8 years was 96, 93, 89 and 77 per cent respectively after SPK, and 93, 75, 57 and 47 per cent respectively after KTA (P = 0.018 at 8 years).

CONCLUSION

The addition of pancreatic transplantation prolongs life in type 1 diabetic patients with renal failure compared with renal transplantation alone.

Macrovascular events after kidney-pancreas transplantation in type 1 diabetic patients

BACKGROUND

There are few studies concerning the effect of kidney-pancreas transplantation (KPTx) on the progression of macrovascular disease in type 1 diabetic patients. The aim of our study was to retrospectively evaluate the incidence of macrovascular events after functioning KPTx.

MATERIALS AND METHODS

We studied 146 patients (96 men and 50 women) who had undergone KPTx from February 1983 to September 2001, with more than 1 year of evolution of both grafts functioning normally. The mean follow-up of the patients after KPTx was 5+/-3 years.

RESULTS

Before KPTx, 29 patients displayed 42 macrovascular events. During the follow-up after transplantation, intermittent claudication remained in 25 patients (86.2%) with 11 new macrovascular events (1 stroke, 1 angina pectoris, 1 myocardial infarction, and 8 minor amputations) in 10 patients (34%). Among the 117 patients without antecedent macrovascular events prior to KPTx, 38 (32.5%) experienced a total of 63 macrovascular events (26 intermittent claudication, 4 stroke, 8 angina pectoris, 7 myocardial infarction, 11 minor amputations, and 7 major amputations). Before transplantation, 88.4% of the patients presented with hypertension, 42.5% a history of smoking, and 14.4% previous treatment for dyslipidmia. After transplantation, we observed an important reduction in the percentage of patients with hypertension (48.6%) and smoking (25.5%), without a change in the prevalence of dyslipemia (19.9%). Hypertension after transplantation was clearly associated with the appearance or persistence of macrovascular events.

CONCLUSION

In our experience, 43% of the transplant recipients present with macrovascular events. It is important to note the elevated prevalence of cardiovascular risk factors in the patients who underwent KPTx.

Pancreas and kidney transplantation

Kidney transplantation is preferred over dialysis for management of end-stage renal disease complicating type I or type 2 diabetes, for those who are eligible. Simultaneous pancreas-kidney (SPK) or pancreas after kidney transplantation (PAK) is an important alternative to kidney transplantation alone for type I diabetes patients if the patient is able to withstand the additional risks of these procedures, because of the benefits of glucose control on other diabetic complications. Pancreas transplantation alone (PTA) is most useful for the treatment of debilitating, frequent hypoglycemia complicating type I diabetes, if renal function is adequate. One-year pancreas graft survival is best after SPK (82%) but has significantly improved after both PAK (74%) and PTA (76%). The I-year kidney graft and patient survival rates after SPK are similar to kidney transplantation alone. Pancreas transplantation normalizes glucose beyond what can be achieved with insulin therapy and has been shown to decrease progression of or improve most, if not all, diabetic end-organ complications using current immunosuppression regimens. However, the diabetologist and endocrinologist should remain involved in the care of the pancreas or kidney transplant recipient for treatment of vascular disease risk factors such as dyslipidemia, surveillance of other diabetic complications including foot ulcers, surveillance and treatment of bone loss, and management of hyperglycemia if it recurs.